The death of a physicist leads Brennan and Booth to a well-known research institute, where the deceased had been part of a controversial study that was likely the reason for a number of threats against her life. Meanwhile, Sweets intervenes when Angela's f (more…)The death of a physicist leads Brennan and Booth to a well-known research institute, where the deceased had been part of a controversial study that was likely the reason for a number of threats against her life. Meanwhile, Sweets intervenes when Angela's father, ZZ Top guitarist Billy F. Gibbons, comes looking for Hodgins.